The Avengers Endgame Time Travel Conundrum – EXPLAINED

http://rowdyc.com/the-avengers-endgame-time-travel-conundrum-explained/

For those not aware of what the movie is about, here’s the basic summary: Five years after the Mad Titan Thanos used the Infinity Stones to wipe out half of all life in the universe and then destroyed the Stones to prevent anyone from undoing his work, the remnants of Earth’s Mightiest Heroes have discovered a possible plan to fix everything – use the temporal peculiarities of the Quantum Realm to travel back in time, retrieve the Stones from the past and use them to undo Thanos’ mass murder. They must do this, however, without changing anything else that has occurred in the past five years; this is the only way Tony Stark agrees to help, as he insists he must be allowed to keep what he has gained in that time – specifically, his daughter Morgan.

Thus, the movie’s writers, Christopher Markus and Stephen McFeely, have a problem. They must make a story where the Avengers go back and take artifacts from the past and return to their time with them, but the present they return to cannot have been changed in any way from the actions they performed in the past – which, of course, contradicts what most people have been told how time travel works in almost every other time travel themed work of fiction ever.

This paradox is brought up in the movie itself, as Scott “Ant-Man” Lang and James “War Machine” Rhodes bring up two questions: 1. Won’t taking the Infinity Stones in the past mean Thanos will never get them, so the problem is already solved, and 2. Wouldn’t it then be even better to go further back and outright kill Thanos as a baby? They bring up several time travel movies and TV shows, including Star Trek, Back to the Future, The Terminator, Quantum Leap, Bill and Ted’s Excellent Adventure and even Hot Tub Time Machine, to say how they’ve always figured that’s how time travel works. Bruce “The Hulk” Banner immediately dismisses them with the following:

“I don’t know why everyone believes that, but that isn’t true. Think about it. If you travel to the past, that past becomes your future, and your former present becomes your past – which can’t now be changed by your new future!”

It seems like an excessively convoluted way to explain how changing the past doesn’t change the future while not really explaining anything. However, there IS one way to effectively explain how this can possibly happen – IF you take one of the few works of fiction related to time travel that Lang and Rhodes DIDN’T mention.

That would be William Sleator’s 1990 book Strange Attractors, which I happened to read back in junior high (roughly about the same time the book was originally published). I’ll spare you the full details of the plot, but here’s the time travel theory the book presents: When you travel back in time, you end up splitting reality into two timelines, and the second, just-created timeline is the one you actually travel to. It is possible to return to your original timeline provided you return at the exact moment you left or later, but the actions you perform in “the past” only affect the second timeline. You can’t change what has already happened in your original timeline. (UNLESS, of course, in the case of this movie, you have the time-and-reality-altering powers of the Infinity Stones.) This may be very similar to the “multiple timeline theory” that has been presented to explain the complexities of the Legend of Zelda video game series.

One can argue that this is what happens in Avengers: Endgame. When the Avengers travel back in time, they create a new timeline, and this is the timeline where they get (most of) the Infinity Stones they need and then take them back to their timeline. It is in this new time line where:

– Thor and Rocket extract the Reality Stone-containing Aether from Thor’s old love Jane Foster.

– Rhodes and Nebula get the Power Stone before Peter Quill steals it on the planet Morag.

– Black Widow and Hawkeye, in one of the most gut-wrenching moments of the whole movie, work to obtain the Soul Stone before Thanos discovers its location.

– Steve “Captain America” Rogers gets Loki’s scepter with the Mind Stone away from the SHIELD/HYDRA agents that took it after The Battle Of New York (I always wondered how HYDRA got ahold of the scepter!).

Of course, the Avengers are unable to get the Tesseract with the Space Stone, and Loki escapes with it. Therefore, Steve and Tony must travel FURTHER back in time to 1970 where they can acquire, in the same location, both the Tesseract and enough Pym Particles needed to return to their timeline. By this logic, they have now created a THIRD timeline, but one that we won’t be discussing that much of here.